At present, with the continuous development of display techniques, a dual-view display capable of providing different display images for different users by using a same display screen has been developed. The dual-view display may be mainly applied to vehicle-mounted display devices. With the function of realizing different images at different view angles by using a single display screen, the dual-view display may realize display functions of two displays by using a single display, so that the cost and occupied space of display devices may be greatly reduced.
Specifically, as shown in FIG. 1, at present, a dual-view display has the following basic requirements for a display angle: the range of a visual angle is 22.5-45 degrees; and, to achieve better dual-view display effects, a center of the field of view is preferably at about 30 degrees, and the specific setting may be determined according to practical application of the display device. Further, on this basis, the prior art provides a solution for realizing dual-view backlight by disposing multiple layers of prism films on a light guide plate (specifically referring to Chinese Patent Application No. 200810170130.4, Publication No. CN101398569A), in which the multiple layers of prism films may include a group of corresponding prism films of which the prism axes (ridges of prisms) are configured in parallel in upper and lower direction with respect to a liquid crystal image, and a group of corresponding prism films of which the prism axes are configured consistently in left and right direction with respect to the liquid crystal image. In the above patent application document, with a backlight module having the multiple layers of prism films, high light condensation characteristics and relatively high brightness may be achieved in left and right direction, so that it can be applicable to dual-view displays mounted in vehicle navigation devices, etc.
However, in the backlight module or the dual-view display having the backlight module provided in the above patent application document, the multiple layers of prism films with relatively complicated structure are used to realize dual-view backlight, so that the structure of the dual-view backlight module is relatively complicated; moreover, due to the presence of the multiple layers of prism films, the thickness of the dual-view backlight module and/or the dual-view display will be increased to a certain extent, which is disadvantageous for the lightening and thinning of a display device. Therefore, it is necessary to provide a new dual-view backlight solution to solve the above problems.